Algebraic systems and pushdown automata

Abstract

This survey paper serves two purposes: Firstly, we consider cycle-free algebraic systems (with respect to a given strong convergence) as a generalization of the usually considered proper systems (with respect to the discrete convergence). Secondly, we develop in a parallel manner the theory of these cycle-free algebraic systems over an arbitrary semiring and the theory of arbitrary algebraic systems over a continuous semiring. In both cases we prove that algebraic systems and weighted pushdown automata are mechanisms of equal power. © 2011 Springer-Verlag Berlin Heidelberg.